Juli Peretó, from the Institut Cavanilles de Biodiversitat i Biologia Evolutiva at the University of Valencia, Spain, is interested in the origin and early evolution of life, the evolution of metabolism, and the history of ideas on the natural origin and the artificial synthesis of life. His current projects include metabolic modeling from complete genomes of endosymbionts, the evolution of metabolism by symbiosis, and the minimal cell concept. He has been invited by Jaume Bertranpetit (UPF).